fix: re-register dotnet for core22 (#4841)

Signed-off-by: Callahan Kovacs <[email protected]>

snapcraft/application.py

@@ -85,10 +85,11 @@ def _get_esm_error_for_base(base: str) -> None:
 class Snapcraft(Application):
     """Snapcraft application definition."""
 
+    _known_core24: bool
+    """True if the project should use the core24/craft-application codepath."""
+
     def __init__(self, *args, **kwargs) -> None:
         super().__init__(*args, **kwargs)
-        # Whether we know that we should use the core24-based codepath.
-        self._known_core24 = False
         self._parse_info: dict[str, list[str]] = {}
 
         # Locate the project file. It's used in early execution to determine
@@ -99,22 +100,40 @@ def __init__(self, *args, **kwargs) -> None:
             self._snapcraft_yaml_path: pathlib.Path | None = self._resolve_project_path(
                 None
             )
+            with self._snapcraft_yaml_path.open() as file:
+                self._snapcraft_yaml_data = util.safe_yaml_load(file)
         except FileNotFoundError:
-            self._snapcraft_yaml_path = None
+            self._snapcraft_yaml_path = self._snapcraft_yaml_data = None
+
+        self._known_core24 = self._get_known_core24()
 
         for craft_var, snapcraft_var in MAPPED_ENV_VARS.items():
             if env_val := os.getenv(snapcraft_var):
                 os.environ[craft_var] = env_val
 
+    def _get_known_core24(self) -> bool:
+        """Return true if the project is known to be core24."""
+        if self._snapcraft_yaml_data:
+            base = self._snapcraft_yaml_data.get("base")
+            build_base = self._snapcraft_yaml_data.get("build-base")
+
+            # We know for sure that we're handling a core24 project
+            if "core24" in (base, build_base) or build_base == "devel":
+                return True
+
+        return False
+
     def _get_app_plugins(self) -> dict[str, PluginType]:
         return plugins.get_plugins(core22=False)
 
     @override
     def _register_default_plugins(self) -> None:
         """Register per application plugins when initializing."""
         super()._register_default_plugins()
-        # dotnet is disabled for core24 because it is pending a rewrite
-        craft_parts.plugins.unregister("dotnet")
+
+        if self._known_core24:
+            # dotnet is disabled for core24 and newer because it is pending a rewrite
+            craft_parts.plugins.unregister("dotnet")
 
     @override
     def _configure_services(self, provider_name: str | None) -> None:
@@ -181,22 +200,23 @@ def _extra_yaml_transform(
 
     @override
     def _get_dispatcher(self) -> craft_cli.Dispatcher:
-        # Handle "multiplexing" of Snapcraft "codebases" depending on the
-        # project's base (if any). Here, we handle the case where there *is*
-        # a project and it's core24, which means it should definitely fall into
-        # the craft-application-based flow.
-        if self._snapcraft_yaml_path:
-            with self._snapcraft_yaml_path.open() as file:
-                yaml_data = util.safe_yaml_load(file)
-            base = yaml_data.get("base")
-            build_base = yaml_data.get("build-base")
+        """Handle multiplexing of Snapcraft "codebases" depending on the project's base.
+
+        The ClassicFallback-based flow is used in any of the following scenarios:
+          - there is no project to load
+          - for core20 remote builds if SNAPCRAFT_REMOTE_BUILD_STRATEGY is not "disable-fallback"
+          - for core22 remote builds if SNAPCRAFT_REMOTE_BUILD_STRATEGY is "force-fallback"
+
+        The craft-application-based flow is used in any of the following scenarios:
+          - the project base is core24 or newer
+          - for the "version" command
+        """
+        if self._snapcraft_yaml_data:
+            base = self._snapcraft_yaml_data.get("base")
+            build_base = self._snapcraft_yaml_data.get("build-base")
             _get_esm_error_for_base(base)
-            if "core24" in (base, build_base) or build_base == "devel":
-                # We know for sure that we're handling a core24 project
-                self._known_core24 = True
-            elif any(arg in ("version", "--version", "-V") for arg in sys.argv):
-                pass
-            elif "remote-build" in sys.argv and any(
+
+            if "remote-build" in sys.argv and any(
                 b in ("core20", "core22") for b in (base, build_base)
             ):
                 build_strategy = os.environ.get("SNAPCRAFT_REMOTE_BUILD_STRATEGY", None)
@@ -223,7 +243,9 @@ def _get_dispatcher(self) -> craft_cli.Dispatcher:
                     and build_strategy == "force-fallback"
                 ):
                     raise errors.ClassicFallback()
-            else:
+            elif not self._known_core24 and not any(
+                arg in ("version", "--version", "-V") for arg in sys.argv
+            ):
                 raise errors.ClassicFallback()
         return super()._get_dispatcher()
 

tests/spread/core24/dotnet/snapcraft.yaml

@@ -0,0 +1,18 @@
+name: dotnet-hello
+base: core24
+version: '1.0'
+summary: a simple dotnet snap
+description: a simple dotnet snap
+
+confinement: strict
+
+apps:
+  dotnet-hello:
+    command: dotnet
+
+parts:
+  hello:
+    plugin: dotnet
+    source: .
+    dotnet-self-contained-runtime-identifier: linux-x64
+    build-snaps: [dotnet-sdk]

tests/spread/core24/dotnet/task.yaml

@@ -0,0 +1,11 @@
+summary: Build a snap with the dotnet plugin
+
+restore: |
+  rm -rf ./*.snap
+
+execute: |
+  # Unset SNAPCRAFT_BUILD_ENVIRONMENT=host.
+  unset SNAPCRAFT_BUILD_ENVIRONMENT
+
+  # dotnet is disabled for core24 until the dotnet sdk snap is rewritten
+  snapcraft pack 2>&1 | MATCH "plugin not registered: 'dotnet'"

tests/spread/plugins/craft-parts/build-and-run-hello/dotnet-hello/dotnet.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <RuntimeIdentifier>linux-x64</RuntimeIdentifier>
+    <InvariantGlobalization>true</InvariantGlobalization>
+  </PropertyGroup>
+</Project>

tests/spread/plugins/craft-parts/build-and-run-hello/dotnet-hello/hello.cs

@@ -0,0 +1 @@
+Console.WriteLine("hello world");

tests/spread/plugins/craft-parts/build-and-run-hello/dotnet-hello/snap/snapcraft.yaml

@@ -0,0 +1,18 @@
+name: dotnet-hello
+base: core22
+version: '1.0'
+summary: a simple dotnet snap
+description: a simple dotnet snap
+
+confinement: strict
+
+apps:
+  dotnet-hello:
+    command: dotnet
+
+parts:
+  hello:
+    plugin: dotnet
+    source: .
+    dotnet-self-contained-runtime-identifier: linux-x64
+    build-snaps: [dotnet-sdk]

tests/spread/plugins/craft-parts/build-and-run-hello/task.yaml

@@ -10,6 +10,7 @@ environment:
   SNAP/python: python-hello
   SNAP/qmake: qmake-hello
   SNAP/maven: maven-hello
+  SNAP/dotnet: dotnet-hello
 
 prepare: |
   #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
@@ -28,6 +29,7 @@ restore: |
   # Undo changes to hello
   [ -f hello ] && git checkout hello
   [ -f hello.c ] && git checkout hello.c
+  [ -f hello.cs ] && git checkout hello.cs
   [ -f subdir/hello.c ] && git checkout subdir/hello.c
   [ -f hello.js ] && git checkout hello.js
   [ -f main.go ] && git checkout main.go
@@ -72,6 +74,8 @@ execute: |
     modified_file=hello
   elif [ -f hello.c ]; then
     modified_file=hello.c
+  elif [ -f hello.cs ]; then
+    modified_file=hello.cs
   elif [ -f subdir/hello.c ]; then
     modified_file=subdir/hello.c
   elif [ -f hello.js ]; then

tests/unit/conftest.py

@@ -23,7 +23,7 @@
 
 import pytest
 import yaml
-from craft_parts import Features, callbacks
+from craft_parts import Features, callbacks, plugins
 from craft_providers import Executor, Provider
 from craft_providers.base import Base
 from overrides import override
@@ -37,6 +37,13 @@ def unregister_callbacks(mocker):
     callbacks.unregister_all()
 
 
+@pytest.fixture(autouse=True)
+def reset_plugins():
+    # craft-part modifies a dictionary of plugins that doesn't get reloaded between tests
+    # 'unregister_all()' resets to the dictionary to the default value
+    plugins.unregister_all()
+
+
 @pytest.fixture
 def snapcraft_yaml(new_dir):
     """Return a fixture that can write a snapcraft.yaml."""

tests/unit/test_application.py

@@ -20,6 +20,7 @@
 from textwrap import dedent
 
 import craft_cli
+import craft_parts.plugins
 import pytest
 import yaml
 from craft_application import util
@@ -309,13 +310,45 @@ def test_application_plugins():
     assert "kernel" not in plugins
 
 
-def test_application_dotnet_not_registered():
-    """dotnet plugin is disable for core24."""
+@pytest.mark.parametrize(
+    ("base", "build_base"),
+    [
+        ("core20", None),
+        ("core20", "core20"),
+        ("core20", "devel"),
+        ("core22", None),
+        ("core22", "core22"),
+        ("core22", "devel"),
+    ],
+)
+def test_application_dotnet_registered(base, build_base, snapcraft_yaml):
+    """dotnet plugin is enabled for core22."""
+    snapcraft_yaml(base=base, build_base=build_base)
     app = application.create_app()
 
-    plugins = app._get_app_plugins()
+    app._register_default_plugins()
+
+    assert "dotnet" in craft_parts.plugins.get_registered_plugins()
+
+
+@pytest.mark.parametrize(
+    ("base", "build_base"),
+    [
+        ("core24", None),
+        ("core24", "core20"),
+        ("core24", "core22"),
+        ("core24", "core24"),
+        ("core24", "devel"),
+    ],
+)
+def test_application_dotnet_not_registered(base, build_base, snapcraft_yaml):
+    """dotnet plugin is disabled for core24 and newer bases."""
+    snapcraft_yaml(base=base, build_base=build_base)
+    app = application.create_app()
 
-    assert "dotnet" not in plugins
+    app._register_default_plugins()
+
+    assert "dotnet" not in craft_parts.plugins.get_registered_plugins()
 
 
 def test_default_command_integrated(monkeypatch, mocker, new_dir):
@@ -484,3 +517,26 @@ def test_run_envvar_invalid(snapcraft_yaml, base, monkeypatch):
         "'SNAPCRAFT_REMOTE_BUILD_STRATEGY'. Valid values are 'disable-fallback' and "
         "'force-fallback'"
     )
+
+
+@pytest.mark.parametrize(
+    ("base", "build_base", "is_known_core24"),
+    [
+        ("core20", None, False),
+        ("core20", "core20", False),
+        ("core20", "devel", False),
+        ("core22", None, False),
+        ("core22", "core22", False),
+        ("core22", "devel", False),
+        ("core24", "core22", True),
+        ("core24", None, True),
+        ("core24", "core24", True),
+        ("core24", "devel", True),
+    ],
+)
+def test_known_core24(snapcraft_yaml, base, build_base, is_known_core24):
+    snapcraft_yaml(base=base, build_base=build_base)
+
+    app = application.create_app()
+
+    assert app._known_core24 == is_known_core24